Balancing device



June 16, 1953 s, F, ANDERSON 2,641,877

BALANCING DEVICE I Filed Jan. 17, 1952 Inl/enar Alm, 5l. @wmv Patented June 16, r1953 UNITED f-sTATEs- PATENT, oFF-ici:

' BALANCING `DEVICE Swan F.Anders*on, Rockford, Ill.,.assignor ofv one- 'half to Ralph F. Anderson, Rockford, Ill.

*Appliation January'rz, 1952, serial No. 266,987

Y 1 Y Y This invention relates toa method and an apparatus by which wheels such as grinding wheels, polishing wheels, buing Wheels and the like, hereinafter referred collectively as abrasive wheels," are brought into balance so as-to rotate with a minimum of transaxial movement during use.

Wheels of the character referredto above commorily are rotated at high speeds, and vas manui factured and' sold are vusually not well enough balanced for best performance. vIthastherefore been common practicefor-the user to balance the wheel when'placed on the arbor inorder toproduce smooth and substantially vibrationless operation. This has largely been a trial and error Yprocedure as distinguished from a denite se- `quence-of steps by kwhich the point of balance is directly and unerringly approached. n Furthermore, even though -a Wheel had beenbalanced on the arbor, its removal andsubsequent replacement on the arbor have necessitated a repetition of the balancing operation.

iclaims. (orsi- 169) Amongthe important objects of the inventionv ditionv of' balance is once determined;A may ybe removed Aand replaced on` the arbor and the v.Wheel unerringly brought to balanced condition -without the necessity for av rebalancing operation. Another object of the invention isfthe provision of balancing means adapted to replace the fconventional side ange of an abrasive wheel and arranged to be held in assembled relation with vthe fwheel by means of ythe-.usual lclamping nut carried on the arbor.

A further object of the invention is theprovi- .sion of a method of 'balancing abrasive wheels .wherein the time required for effecting balance is reduced to a minimum and the usual trial and error method eliminated.l

Other objects and advantages will be apparent from the following description and the `accompanying drawings', in which: y

Figure 1 is a perspective view of a grinder stand fis the provision of means for balancing an abrasive Wheel such that the wheel, when its con- Y 2 by the numeral 8 carried Aon an arbor 9 driven from a motor vI I forming part of a conventional grinding stand I2. Obviously, the specific form of 'the mechanism for driving the wheel is not of importance in connection With the invention.V

The balancing attachment comprises in this embodiment two plates indicatedY generally b-y the numerals I3 andvlll each having a central opening for the reception of a thimble I5'which serves to maintain the two plates in assembledrelationship. The thimble is in the form of atubular member passing through the centralopenings of the plates and having a ange vI6 at one end adapted to bear against the outer facev of the plate I4, as best shown in Figs. 6 and '7. The opening in the thimble I5 is of such size as to be snugly received on the arbor 9 with the plates I3 and I4 carried` thereon in the manner' shown in Fig. 7 so that when the' arbor nut I 3 is `tightened against `vthe shoulder I6,` the plate `I3 is pressed against the Vouter side ofthe wheel. Nor'- mally a spacer plate I9 is interposed on the arbor between the inner side of the wheel and a collar n 4or other stop y2I carried on the arbor. In this manner whenthe nut I8 is tightened, the Wheel is gripped Vbetween the spacer plate I9 and the `plates I3 and I4.

As bestshown in Figs. 6 and 7 the plate I3 of .the present embodiment is provided With'a central frusto-conical portion 22 and la peripheral coplanar rim 23 so' that when the parts are brought to the position shown in Fig. '7 the'pe- Vripheral rim 23 will seat against the side of the @Wheel andthe frusto-conicalY portion will be spaced from the wheel in the manner shown, thus Aprovidingacertain amount of resiliency as between the nut I8 and the wheel, and providing a stable support'against the wheel in an area atsome'distance from the axis of the arbor.- In

showing the invention as incorporated With a l grinding wheel;

Figs. 2, 3, 4 and -.5are elevational views illustrating steps of balancing a grindingwheel inac- `cordance` with the invention;`

Fig. 6 is a transverse section throughthe balancing attachmentjand Fig. 7 is a vfragmentary section on the line 'IQ-1 of Fig. 1.

Figure 1 ofthe drawings shows the preferred embodiment of the invention as combined with a conventional grinding wheel indicated generally this instance the plate I4 is of smaller dimensions than the plate I3 so that'its perimeter termi nates substantially at the inner edge of the portion 23 (though this, of course, is not essential), and this plate likewise has a frusto-conical shape. The plates I3 and Ill are in dynamic balance with respect to the axis of the arbor and the axis of the central openings of the plates except for a small portion of each, which in this instance isr provided by an opening 24 in the plate I3 and an opening 25 in the plate I4. These openings are such as to remove or omit identi- .cal amounts of metal from the two plates at equal ldistances from the axis of the central openings so that when the two openings are placed on the same diameter ofthe wheel, they do not affect the r'segment of the wheel.

. 3 balance of the assembly. In the present instance these are formed by drilling equal sized holes through the plates I3 and I4 which are formed of sheet metal of equal thickness, the center lines of these holes being at equal distances from the axis of the central openings.

It is convenient, though not essential, to make the plates I3 and I4 of circular configuration so that when the plate I4 is placed in face to face relation to the plate I3 as shown in the drawings, the plate I3 will have a marginal exposed area which in this instance is substantially the width of the portion 23. The plate I3 is provided with indicia as indicated at 26 in the form of graduations arranged along its perimeter in the exposed area, which graduations extend through. 90

about the axis of the central opening. Conveniently these graduations are numbered or lettered progressively from a point disposed at 90 with respect to a diameter passing through the axis and through the center of the opening 24 land extending to the radius on theopposite side of the axis from the opening 24. Likewise the plate I4 has indicia indicated at 27 extending progressively from a radius disposed at 90 with respect to a diameter passing through the axis and through the center of the opening' 2.5, whichY graduations extend through 90 to the diameter on the opposite side of the axis from the opening 25. In this instance the graduations are vnumbered zero to ten, as will be observed from the-drawings, progressingrirom thel90 radiiin opposite directions in inverse order.

The method of balancing the wheel is illustrated in Figs. 1,-5 in which the numeral 3l in- .dicates a conventional balancing stand or balancing way, such'as are well known in the art. The iirst step illustrated in Fig. 2, comprises introducing a spindle 32 into the opening of the wheel which is shown in this .instance as aconventional grinding wheel.V The `spindle and wheel are then placed on the balancing stand and allowed to come toy rest in the usual manner.

Thereupon a mark suchas shown at 33 is placed vertically on the side of the wheel in anyconvenient permanent manner for indicating the radius dening the center of the unbalanced Thereafter the plates I3 and I4 constituting the balancing attachment are placed on the spindle 32 as shown in Figs. 3 and 5 with the two zeros of the graduations in alignment. This should not disturb the balancing of the wheel but should allow it to rest in the position shown Ain Fig. 3. If desired or more Y convenient the balancing attachment can be assembled with the wheel in the rst instance.'

The operator can at this pointusually estimate roughly theY degree o f unbalance based on the rate at which the wheel swings on the stand and can, therefore, estimate the amount ofadjustment between the two plates, which may be re- ,quired to eilect balance.

parent from Fig. 4 so as to lighten the lower soV or heavy side of the assembly. When the ase sembly is thus brought into balance, the operator places the numeral or other indicia indicated by the graduations 26 and 21 onto the face of the wheel in a permanent fashion. For example, in the illustrated embodiment it is assumed that the assembly came into balance with the numerals 3 in alignment with the line 33 and, therefore, as shown in Fig. 4 the numeral 3 is applied to the face of the wheel. This completes the balancing operation, and at this point the spindle 33 is removed from the wheel and the attachment, and the assembly is mounted on the arbor 9 with the numerals 3 of the two plates in alignment with each other and with the line 33, as a result of which the wheel, when assembled in working position on the arbor, is in balance.

It will be seen that when this operation is completed the wheel 8 may be removed from the arbor for use of a different Wheel on the arbor and may subsequently'be replaced and directly be brought into balance, since the` numerals placed on the face of the wheel and the center line 33 enable the balancing attachment to be unerringly placed in the proper position to effect'balancing of the wheel.

I claim. n Y

1. An attachment for balancing an abrasive wheel comprising disks of generally circular outline arranged in face'to face relation, each having a central opening for the reception ofv an arbor carrying an abrasive wheel, each of said disks having a portion of the metal thereof removed along one vradius of the disk to produce unbalance along a diameter coinciding with said radius, at least one of said disks being dished to provide a peripheral coplanar face on one side of the disk for engagement with the wheel and to space the central portion of the disk from the wheel, graduations along the periphery of each disk extending from directly opposite the aforesaid radius through ninety degrees, the gradu- .ations being identified by indicia progressing in opposite directions, and means for supporting the disks for rotary adjustment with respect to each other about the axis of the central opening.

2. 'Ihe combination recited in claim 1 wherein Athe disks have holes disposed inwardly from the periphery .of the disks arranged to provide equal unbalance to the disks.

E3. The combination of claim 2, ywherein the Yholes in the respective disks are equal in size and are equally spaced from the axis of the central opening.

4. The attachment of claim 1,'wherein said -disks are of sheet metal and said one dished disk is larger in size than the other disk and has an exposed annular marginal area when the disks are arranged in face to face relation.

' SWAN F. ANDERSON.

References Cited; in the le of this patent UNITED STATES PATENTS 2,377,096 Nichols r May 29, 

